As well as publishing a quartely magazine, Drag'n'Drop has been creating a range of books for RISC OS. Their latest release is 'The Application Tutorial and Listings Book for RISC OS computers'
This is a 300 page, spiral bound book (so it sits nicely by your machine open at your selected page) of short programs showing how to write WIMP programs with BBC BASIC on any modern RISC OS machine. Rather than develop one application through the book, there are lots of little, self-contained examples to show different features of the WIMP. So you can just dip in wherever you are interested.
The programs are grouped into chapters with a general theme such as Error Handling, Reporting and Memory, Drag and Drop, Icons, Windows and Menus. There is also a chapter of demonstration Applications such as an Icon Bar clock and a Desktop Solitaire.
Each example includes the code listing, lots of screenshot and detailed explanation of the example code.
There is also an introductory chapter to get you started, but this book assumes a working knowledge of BBC BASIC.
If you are learning BBC BASIC, this not a tutorial to learn it. But once you have grasped the language and want to build Desktop applications, this is definitely the book for you!
You can purchase the book directly from Drag'n'Drop website where you can also download a PDF sample containing some of the examples and see the full contents.